import java.util.*; 
class Student {
private String name;
private String number;
Student(String name, String number) {
    this.name = name;
    this.number = number;
} 
@Override
public String toString()  {
    return String.format("(%s, %s)", name, number);
}
}
public class Students {
public static void main(String[] args) {
    Set students = new HashSet();
    students.add(new Student("Justin", "B835031"));
    students.add(new Student("Monica", "B835032"));
    students.add(new Student("Justin", "B835031"));
    System.out.println(set);

}
}
